"""User-settings request/response schemas.

Enums are enforced at the API boundary (Pydantic ``Literal`` → 422 on bad
input), so the service can trust the values it receives.
"""

from typing import Literal

from pydantic import BaseModel, model_validator

Theme = Literal["system", "light", "dark"]
# Playback quality preference. ``original`` = no transcode; the lower tiers are
# consumed by the (upcoming) transcoding pipeline.
StreamQuality = Literal["original", "high", "medium", "low"]
ScrobbleProvider = Literal["lastfm", "listenbrainz"]


class SettingsOut(BaseModel):
    theme: Theme
    stream_quality: StreamQuality


class SettingsUpdate(BaseModel):
    """Partial update — omitted fields keep their current value."""

    theme: Theme | None = None
    stream_quality: StreamQuality | None = None


class ScrobblingOut(BaseModel):
    enabled: bool
    provider: ScrobbleProvider | None
    username: str | None
    # Whether a session key is stored. The key itself is never returned.
    configured: bool


class ScrobblingUpdate(BaseModel):
    enabled: bool = False
    provider: ScrobbleProvider | None = None
    username: str | None = None
    # Write-only scrobbler session key / user token. Omit to keep the stored one.
    session_key: str | None = None

    @model_validator(mode="after")
    def _provider_required_when_enabled(self) -> ScrobblingUpdate:
        if self.enabled and self.provider is None:
            raise ValueError("provider is required when scrobbling is enabled")
        return self